Rotary liquid piston machines



Sept. 27, 1966 A. J. MEYER ROTARY LIQUID PISTON MACHINES 5 Sheets-Sheet 1 Filed Jan. 11, 1965 mN mi w: mm

INVENTOR.

Sept. 27, 1966 A. J. MEYER ROTARY LIQUID PISTON MACHINES 5 Sheets-Sheet 2 Filed Jan. 11, 1965 mm Nb 5 0m p 7 66 A. J. MEYER 3,275,222

ROTARY LIQUID PISTON MACHINES Filed Jan. 11, 1965 5 Sheets-Sheet 5 Sept. 27, 1966 Filed Jan. 11, 1965 A. J. MEYER ROTARY LIQUID PISTON MACHINES 5 Sheets-Sheet EVAPORATOR GAS-AIR llllllHlllf Hlllllllllll LI OUIS LIOUID SEPARATOR PSI INVENTOR BY w 7 Sept. 27, 1966 A. J. MEYER ROTARY LIQUID PISTON MACHINES 5 Sheets-Sheet 5 Filed Jan. 11, 1965 United States Patent 3,275,222 ROTARY LIQUID PISTON MACHINES Andre J. Meyer, 848 N. Jackson Drive, Fayetteville, Ark. 72701 Filed Jan. 11, 1965, Ser. No. 424,581 15 Claims. (Cl. 230116) This invention relates to rotary liquid piston engines and to the combination of such an engine with a rotary liquid piston pump.

The basic idea of rotary liquid piston gas pumps was originated by Nash (Patent No. 953,222), who created a displacement structure by providing a cylindrical case or housing, in which a rotor or impeller with radial vanes is eccentrically mounted. When the rotor revolves and the case is filled with sufficient water to keep all vane tips submerged, a liquid ring is formed, the inside diameter of which approaches the rotor hub much closer on one side than on the other. Therefore the empty space between a pair of adjacent vanes varies from a minimum to a maximum to that minimum again during each revolution. Provision of suitable inlet and outlet'ports as well as proper sealing structures is needed to use this variable space for pumping.

To better understand the rotary liquid piston principle, it must be realized that the liquid is subjected to a centrifugal force field, which is very much stronger than gravitation. While the acceleration of gravity (g) in the lower atmosphere is nearly constant over the whole surface of the earth, the centripetal acceleration of the liquid in the rotary liquid piston pump is inversely proportional to the local radius of rotation and directly proportional to the square of the liquid velocity, which roughly equals the peripheral speed of the impeller.

In order to prevent the reversal of liquid flow direction under the influence of local high gas pressure, the rotor diameter and speed must be selected so, that the stagnation pressure of the liquid exceeds the maximum desired gas pressure. Consequently in practical pumps the accelerations of the liquid vary from 160 g. in a vacuum pump to 2000 g. or more in high pressure pumps. As a result, dependent on the application, the weight of water in the liquid ring varies between 5 and 62.5 tons per cubic foot. This weight is supported by the housing wall and since all weight vectors are directed radially outward and gravitational effects are negligible, the inside water level of the ring must be concentric with the casing wall, regardless of the position of the vanes relative to the liquid. Evidently no small disturbance can deform the level of water of such high specific gravity.

As the impeller revolves, the inner liquid ring surface moves in and out of the chambers or buckets formed by each adjacent pair of rotor vanes. Therefore this surface acts like the top of a piston in a cylinder, except insofar that the liquid piston area varies to fit the shape of the bucket. The machine is indeed a displacement structure with a liquid piston capable of raising the static pressure of a gas without appreciably affecting its kinetic energy. It is not a flow machine like a centrifugal pump or turbine in which static pressure changes are the result of transformations from kinetic into potential energy and vice versa.

As the art of liquid piston pumps developed, the simple cylindrical case was abandoned in favor of double, triple or even multiple lobe housings, which made the pump double, triple or multiple acting. In principle, however they remained liquid piston displacement structures, even though the ambiguous name of hydro turbine obscures that fact.

Although other displacement structures have been used for either pumps or motors, no attempt was made to adapt rotary liquid piston machines of the type described for the purpose of engines, although the following comparisons indicate that they may have certain advantages for this application.

Conventional piston engines require chemically rich mixtures of high grade fuel and air, which in the motor are contaminated with residual exhaust gases. As a result the combustion products are only partially oxidized, obnoxious, poisonous and cause smog. The gases are released at high pressure, which means energy loss and noise. These engines further operate on a high frequency batch process, requiringa large number of cylinders in order to obtain a reasonably smooth torque. This leads to complexity and bulk, so that a modern V-8 usually occupies a space of more than times the engine displacement per revolution.

In a rotary liquid piston engine the compression, combustion and expansion take place in separate specialized units. Like in gas turbines the airfuel ratio will be 1 to 4 times the stoichiometric ratio. This means complete combustion even of low grade fuels, clean exhaust, and further, because the combustion products are expanded to atmospheric pressure, there will be lower exhaust temperatures, higher efficiency and less noise. The zero clearance volume will also improve the pump efliciency. Besides that, if there are n vanes on the impeller, there are 2n pistons completing a cycle each revolution. Thus the torque will be smooth without complication, in fact the whole rotor assembly can be made as a single permanent mold casting, the only moving part in the machine. Furthermore all dynamic and gas forces are inherently balanced, so that the rotor bearings carry only the rotor weight. Finally the machine will occupy a space of less than 40 times its expander displacement per revolution, and a single combustion chamber, without ignition device other than a glowplug for starting, will take care of the combustion of the gases delivered by the gas and air pumps.

Obviously a large and varied number of applications of this invention can be made. By way of example a motorcompressor, more specifically a refrigerant compressor driven by a natural gas-air engine will be discussed. Obviously a compressor for any other gas, including one for natural gas pumping stations, is very similar in principle, only an air compressor requires two instead of four pumps. All these machines have no power output shaft, therefore an industrial natural gas-air engine driving a shaft with sheave for multiple V-belt drive will also be disclosed. It must be understood that a mixture of air with any fuel may be used to drive the motor, Which furnishes the energy needed to raise the pressure of any gas, vapor or liquid, or a mixture there-of, or to deliver shaft power to any mechanical contrivance.

One object of the invention is the provision of a rotary liquid piston engine capable of producing power smoothly, efiiciently and silently without the emission of objectionable exhaust gases.

Another object is the provision of a rotary liquid piston machine combining a gas motor and a gas compressor in such a manner that the drive torque developed by the motor is transmitted internally straight-away to the compressor. Thus the torque reactions on the motor and pump housings are balanced against each other, so that no reaction effect is transmitted to the surroundings.

Another object is to provide a rotary motor-compressor unit having a rotor supported on bearings not subjected to gas or dynamic loads and having no other moving parts, so that long trouble free life may be expected.

Still another object is to provide a rotory motor-gas pump in which the amount of axial gas leakage is minimized by the elimination or reduction of the axial pressure difference between adjacent elements of the machine.

Other objects and advantages will hereinafter appear.

In the drawings:

FIGURE 1 is a plan view of the motor-compressor.

FIGURE 2 is a side elevation.

FIGURE 3 is an end view of the motor side.

FIGURE 4 is an end view of the pump side.

FIGURE 5 is a bottom view.

FIGURE 6 is a partial longitudinal section limited to the length of the stator spindle. The latter is shown in side view, otherwise the section is substantially in the vertical plane, except as indicated by 66 of FIGS. 23 and 24.

FIGURES '7 through 22 are normal cross sections through the stator spindle, at the stations in FIG. 6 that carry the same number as the section. All sections are drawn looking from left to right.

FIGURE 23 is a cross section through the motor driven by combustion products, taken along 23-23 in FIG. 6.

FIGURE 24 is a cross section through the refrigerant compressor taken along 24-24 in FIG. 6.

FIGURE 25 is an end view of the cooling liquid circulation unit mounted on the stator spindle at the motor side.

FIGURES 26a, 26b and 260 are partial sections along the line 2626 in FIG. 25.

FIGURE 27 is an end view of the air entrance and make-up water supply unit mounted on the stator spindle at the pump side.

FIGURES 28a and 28b are partial sections along the line 2828 in FIG. .27.

FIGURE 29a is a section along the line 29a29a in FIG. 26b.

FIGURE 29b is a section along the line 29b-29b in FIG. 260.

FIGURE 30 is a graph showing the pressure vs. rotation angle variation for all gases used in the refrigerant compressor.

FIGURES 31a and 3112 are polar diagrams of gas pressures in an air motor and an air pump, before and after advancing the pump 60.

FIGURE 32 is a piping diagram or flow sheet for the refrigerator system.

FIGURE 33 is a longitudinal section in the vertical plane of a gas-air engine with power output shaft.

FIGURE 34 is the end elevation of the water inand outlet units as seen from plane 3434 in FIG. 33.

FIGURES 35 through 42 are normal sections of the stator spindle at the stations in FIG. 33 carrying the corresponding number. All sections are taken looking from left to right.

The refrigerant compressor comprises a stationary housing 51 closed by the end covers 52, which support a shaft or spindle 53 (FIG. 6). In operation all these parts are stationary, the covers are fastened to the stator housing by means of the screws 54 and rotation of the stator spindle is prevented by the timing screw 55 in the cover on the pump side. This screw is provided with a dog point 56 .that fits in a slot 57 milled in the shaft. Axial move ment of the spindle relative to the housing is prevented by the nut 58 engaging the thread 59 on the shaft. When this nut is tightened all parts contacting the outside diameter of the shaft between the nut and the shoulder 60 on the shaft are being compressed against the hub 61 of cover 52. The parts between the cover and the nut are provided with 0 rings 62, so that the spindle is not only rigidly held to the covers, but also the interior of the stator is sealed against leakage along the shaft to the outside.

The end location described above is used on both sides of the shaft, like par-ts being identified 'by the same numbers, but only one timing screw is shown, it is 90 out of place where shown.

The end sections of the housing may be round, but in-the motor and pump areas the cross-section is an oval of the same dimensions. The major axis of the oval in the These radii describe arcs subtending about 15 on either side of the minor axis, which will be called the flanks of the oval. As shown they blend smoothly into the arcs forming what will be called the lobes. The machine will function, when the flanks intersect .the lobes, but may develop noise due to water hammer, unless they have common tangents.

Partition walls 64, 65 and 66 run radially inward from the outer wall of the stator housing. They are bored out to the rotor outside diameter plus a small clearance, so that the rotor assembly, mounted on the spindle can he slipped into the housing from either side after both covers are removed.

The rotor consists of a number of parts that are stacked up, dowelled and bolted together, so as to form a single rigid assembly, supported on the stator spindle by means of one ball bearing 67 and one roller bearing 68. The latter has a removable inner race 69, so that no axial bearing loads can result from any difference in thermal expansion between rotor and shaft. In FIGURE 6, from the left or motor side to the right or pump side, the rotor consists of the roller bearing retainer 70, which also houses the oil seal 71, the roller bearing housing 72 with the oil seal 73, the combined air and combustion product motor expansion wheels 74 and 75, the impeller for the air pump 76, refrigerant pump 77, another air pump 78, the gas pump 79, the ball bearing housing with the oil seal 81 and the bearing retainer 82 with oil seal 83.

All motor wheels and pump impellers consist of a radial disc from one face of which a series of vanes are projecting in an axial direction. The pattern of vanes is identical in all cases and consists of .a number of equally spaced radial vanes 84 as shown in FIGS. 23 and 24, some of which are provided with bosses 85 that are drilled for bolts 86 and bored for ring dowels 87. Short vanes 88 (FIG. 6) are provided on the outside diameter of the bearing housings 72 and 80.

The motor wheels have long vanes for the product gas expander on one side and short vanes for an air motor on the other. In operation, over the whole range of the expansion process, the gas pressure in the two small air motors will be made identical to the pressure of the product gases, so that these cannot leak out axially. Since the air in the air motors is much cooler than the combustion products, the provision of the two small air motors makes it possible to effectively seal against leakage of the cooler air and thus contain the hot gases without trouble. On the roller bearing side the axial seal is accomplished by the oil seal 73, or a double acting seal 203 as shown in FIG. 33 may be used. On the pump side a heavier wall 65 with liquid injection and balanced air pressure, both to be discussed later, will prevent leakage from air motor to air pump and vice versa.

In FIG. 23 the liquid level 89 intersects the stator spindle at the points 90 and 91 and between the level and the spindle there is a gas filled crescent, divided in several spaces or chambers between adjacent rotor vanes. Evidently any chamber, the centerline of which is in the position 92, contains no gas, but as the trailing edge of the leading vane of this chamber passes point 90 on the spindle, the liquid is compelled to rise away from the spindle surface, leaving a vacuum behind. If, however, an intake port 93 is formed in the spindle, gas under pressure may be supplied to destroy the vacuum and fill the space up to the water level.

As the rotor revolves beyond the point of intake opening, the gas volume in the chamber under observation enlarges, so that .the weight of compressed gas it contains increases. This continues until the leading edge of the trailing vane of that chamber reaches the point 94 on the spindle, where the communication between the intake port and the chamber under observation ceases. Further rotation results in more enlargement of the gas volume, so that the gas must expand .to a lower pressure. When the chamber center-line arrives in position 95, which will be called top center, the volume occupied by the gas reaches a maximum value. If point 94 is properly selected, it can be arranged that the gas pressure in top center is atmospheric. In that case the trailing edge of the leading vane of all chambers arriving at top center must line up with the opening edge 96 of the exhaust port 97. The exhaust period lasts until the leading edge of the trailing vane reaches point 91 on the spindle.

It is to be noted that the process described is repeated on the lower half of the shaft, so that each of the twenty chambers shown are charged and discharged twice per revolution. Evidently the displacement per revolution of the motor, measured with the exhaust products completely expanded, equals forty times the volume of gas contained in a chamber, when it is in the top center position.

The process in the refrigerant pump of FIG. 24 starts with the intake opening at 98, where the liquid level intersects the spindle. The intake port 108 closes, when the chamber reaches .top center, where the leading edge of the trailing vane is at point 100, because here the inward stroke of the liquid commences. Compression lasts until the desired maximum pressure of the refrigerant vapor is reached, when the trailing edge of the leading vane is at point 101 at the opening edge of the exhaust port 109. The exhaust takes place at constant pressure and is completed when the leading edge of the trailing vane arrives at the intersection 103 of the liquid level and the spindle, which point coincides with the closing edge of the exhaust port.

From FIGS. 23 and 24 it will be clear, that twice per revolution all vanes are completely submerged in the liquid, while about half their length never comes in contact with any gas, hot or cool. One reason for this situ ation is that the bolt bosses 85 must be kept out of the crescent to avoid difference in compression or expansion in the twenty chambers. In production, if the rotor is cast in one piece, these bosses can be eliminated and hence it will be possible to reduce its diameter by about 20%. This will necessitate an increase in the number of revolutions per minute, since the peripheral speed must be maintained. In that case the space to displacement ratio will reduce from 40 to 34, while the cooling should still be adequate because of the continual wetting.

The intake and exhaust ports 104 and 105 of the two air motors are like those of the combustion products motor, but they are of course much shorter axially, and although the exhaust ports are identical in cross-section, the intake ports are somewhat different, as shown in FIGS. and 11. Also the intake ports of air, refrigerant, air and gas pumps, respectively 106, 108, 110 and 112 are similar, as are the exhaust ports 107, 109, 111 and 113 (see FIGS. 12, 13, 14 and 15).

It will be noted that the refrigerant pump has been placed between two air pumps. This was done because again, as will be shown later, it is possible to eliminate axial pressure differences between air and refrigerant pumps and thus prevent refrigerant losses through the water film between rotor partitions and the stator spindle. This cannot be done with a gas pump adjacent to the refrigerant pump, because the gas pressure must be 5 to 10% higher than the air pressure to promote mixing in the combustion chamber. Furthermore some leakage of gas into the air is not detrimental, since both are to be delivered to the combustion chamber.

Gas: Symbol Air A Combustion products P Natural gas-air mixture G Refrigerant R Water W Lubricant L Furthermore, if the letter symbol is primed, the fluid is at high pressure. Thus in the motors A and P indicate gases flowing toward the motor, while G, A and R are fluids flowing away from the pumps.

FIGS. 7 through 22 show the cross drilled holes needed to connect either the collector and distributor rings, or the intake and exhaust ports with the proper passages. Thus at station 7 the distributor ring 114, which is hollow inside, carries a boss 115, provided with an inlet 116 for the insertion of a pipe to connect it with the combustion chamber outlet shown diagrammatically in FIG. 32. At station 7 (FIG. 6) and in FIG. 7 the cross drilled hole 117 is shown, through which the hot high pressure gases enter the passagesmarked P. These are shown in FIG. 11 to be connected to the intake ports 93 by the holes 118. It is further shown that the exhaust ports 97 are connected to the passage marked P via the holes 119. In FIG. 8 the passages marked P lead the exhaust products by means of the holes 120 to the ring 121 with outlet 122.

The air motors draw compressed air from the hole 123 in the plugs 124. In FIG. 10 this hole is shown to communicate with the intake port 104 via the drilled passage 125. The motors discharge the expanded air via the exhaust port and the hole 126 into the passage P, where it mixes with the expanded combustion products. This mixture leaves the outlet 122, which therefore is marked P-i-A.

The air pumps take in air through the screen 127 surrounding the make-up water supply unit 128 (FIGS. 1, 2 and 5). It enters a passage 129 (FIG. 28a) and reaches first the port via the hole 130 at station 14, while the major part of the air continues to station 12, where it is delivered to the port 106 via the hole 131. The compressed air discharged by the pumps flows from the outlet ports 107 and 111, respectively via the holes 132 and 133 and the A passage, which runs to the motor side to communicate with the hole 123 in the plugs 124 and in the opposite direction to communicate with the ring 134 to the outlet 135.

The refrigerant enters via 136, 19, R, 137 to port 108 at station 13 or section 24 and leaves by route 109, 138, R, 20 to outlet 139.

Natural gas and air, mixed in stoichiometric ratio, are admitted by the path 140, 21, G, 141 at 15 and 112. They leave via 113, 142, G, 22, 143.

In FIG. 6 the collector and distributor rings are shown in such a position that motor outlets and pump inlets, which all are at atmospheric pressure, are turned up, while the high pressure inor outlets are turned down. These positions may be changed by turning the rings in any other radial direction before tightening the nut 58.

Besides the function of many little pistons, the liquid has other duties to perform, such as sealing, cooling and starting.

Further, to prevent the pump discharge gases to be trapped in the machine, it is necessary to actually exhaust some liquid with those gases. Since this liquid is under pressure, it can be recovered, cooled and returned to the machine, where it may serve to cool the hot side of the spindle as well as to seal critical locations. The discharge of the motors being at atmospheric pressure, the retention of a few hot gas bubbles is not serious, since they will reduce in size by cooling and condensation, and later by compression, when the fresh charge enters. Any liquid that escapes with the motor exhaust will be lost, therefore it is necessary to carefully limit the outflow, so that less make-up liquid is needed to maintain the level 89.

In general the liquid will be water, only when very high pressures are required, there is the choice between double staging and the use of a liquid of higher density. Also the gas to be pumped may sometimes be incompatible with water, so that other liquids must be used.

The refrigerant condenser in this disclosure handles Freon 21, which for a home cooling unit can be used between 40 p.s.i. and atmospheric pressure. This low pressure would normally be undersirable, because it requires a larger than usual piston displacement, but it is not objectionable for the rotary machine with its small space to displacement ratio. Further this refrigerant is totally insoluble in water, therefore, also because of its advantage for cooling and easy availability, water is preferred.

The sealing function of the water will now be discussed in detail.

In operation the outside diameter of the rotor is always submerged. In the motor section the gas pressures in the three units are identical, therefore no axial flow of water is possible and consequently no partitions are needed in the stator housing at the separation of air and product gas motors. The same argument applies to the pump section at the separation of Freon and air pumps, and since the gas pressure is only a few p.s.i. higher, also the partition between air and gas pump may be omitted in the housing. However, outside the bearing housings 72 and 80 the stator housing is circular and the gas pressure is atmospheric. Water in these spaces will whirl around at constant speed because of the vanes on the bearing housing. As a result the pressure differences in the water at the partitions 64 and 66 are not high. Neither are they very high at the partition 65, although in any plane through the centerline the radii of curvature at the pump and motor housings and hence the centrifugal forces are unequal. Here, however, whatever leakage may take place in one direction will be compensated for by the same amount of leakage in the opposite direction. Therefore it appears possible to allow a sufficient amount of clearance to prevent a metal to metal contact at the outside diameter of the rotor.

Between the rotor and the stationary spindle it is necessary to prevent leakage of gas. This is of course harder to contain and therefore a more detailed knowledge of the value of the gas pressure everywhere is essential.

FIG. 30 shows that the rates of pressure rise differ for the four gases used in this machine. The curves are for the applicable temperature ranges, considering the variation of specific heat therewith. The angles shown represent the rotation of the centerline of the leading vane of any chamber, and are measured in degrees from top center. Since expansion would take place between about the same temperatures, the curves may be used in reverse to obtain results for expansion.

Inspection of a large scale drawing of this kind shows that the air and product gas curves can be made to practically coincide by starting the compression of the product gas 1 earlier than that of the air. For air and Feron 21 the difference is 4. For expansion of air and product gas the expansion of the latter would have to start simultaneously. By these minor adjustments a perfect balance of axial pressures can be obtained, with the result that axial leakage between the .motors and pumps can be avoided. I To represent the condition at the partition 65, the

pressure variations on the adjacent air motor and air pump have been plotted in a polar diagram FIG. 31a, where the distance P is proportional to the pressure of the air at an angle of A degree from top center. Here and elsewhere in the diagram the subletter m refers to the motor, while p refers to the pump. Further:

I0 is the point where the intake port opens. IC is the point where the intake por-t closes. E0 is the point where the exhaust port opens. EC is the point where the exhaust port closes.

In this diagram the pump and mot-or housing ovals are in line with each other. FIG. 31b shows the same diagram with the pump section rotated through an angle of 60 in the direction of rotation. In this case the high .pressure and also the low pressure areas overlap most of the time. Instead of four long duration pressure surges on the partition there are now eight surges at about half the pressure and during very small time intervals. Theoretically this reduces the leakage to about 15% of that in FIG. 31a, and since there is air leakage both ways, there is no net loss. Hence it may be concluded that also here the axial leakage is insignificant.

Thus the axial gas leakage from motor to motor, from pump to pump and from motor to pump has been made negligible by means of small adjustments in timing and by advancing the whole pump section about 60 with respect to the motor section. Therefore internal leakage must be confined to leakage in an axial direction through the bearing housings 72 and '89 and the oil seals 73 and 81. In a circumferential direction at any of the eight partition walls shown contacting the spindle, there are four critical places, where the gas pressure around the shaft changes, from low to high or from high to low, in a very short distance. To prevent serious leakage at these locations, cooling water under pressure W must be introduced at the four critical points marked in FIG. 31b located in such a manner, that each high pressure area on the shaft is bracketed between two points, where water at a pressure equal to or higher than the maximum gas pressure is injected in the film between rotor and shaft. Evidently, if the rate of water circulation is high, the film thickness can be large and vice versa.

The water circulation is illustrated in FIGS. 25 through 29b. Cooling water enters through the side opening 144 of the liquid circulation unit 145. It passes through the annulus 146, streams along the inner wall of the spindle and via the holes 147 through the wall of the pipe 148 to the inside of that pipe, which is fastened to the unit, and leaves through the opening 149. The pipe is supported at the bore 150 and can be assembled with the unit 145, which is secured to the spindle by means of four studs 151, nuts 152 and lockwashers 153. A gasket 154, inserted between unit and shaft, seals all the open passages in the spindle on the motor side, except the annulus 146.

At the location of the partition walls on the inside of the rotor, holes 155 have been drilled radially inward to meet the annulus 148 or the Water space in the bore 150 at the end of the pipe. These holes 155 pass through the bores containing the plugs 12-4, but these have been provided wit-h circumferential grooves 156, so that some of the cooling water may pass around the plugs to be ejected into the clearance between rotor and shaft. FIG. 2% shows how holes 157 and 155 together cover the critical areas illustrated in FIG. 31!).

The plugs 124 are inserted in the spindle for the purpose of extending the compressed air passage A of FIG. 12 towards the air motors. These plugs are held in position by the springs 15%, which force them against the O ring 159. Other 0 rings 160 prevent leakage of gas or water in the direction of the springs. The plugs are further located and prevented from turning by means of the set screws 162, installed under the spacer ring 163. Like the timing screw 55 the screw 162 has a dog point to fit in a milled slot, this time in the plug 124.

The plug is further provided with a tapped hole 164 to insert a screw to pull it out when desired.

The make-up water enters the inlet 165 of the makeup water supply unit or casting I128. From there some of the water may be supplied to station 16 via the holes 167. It will be preferable, however, to make other arrangements, so as to supply all critical sealing areas with cooling water, and to introduce all make-up water through the tube 168 and the orifices 169 via the holes 13-1, into the intake ports 106 of the air pump at station 12. Then the cooling water can be increased by enlarging the rotor clearances, particularly at the pump side, which will reduce the make-up water requirement.

The tube 168 is pressed into the unit 128 on one side and into a plug 170 on the other to seal it. This plug is provided with an O ring 171 on its outside diameter, so as to prevent cooling water leaking into the air inlet 129. The unit 128 consists of a water inlet platform and a base 172 linked together by four bolt bosses and two bosses for the drilled holes 167. Between all these bosses air may enter to reach the passage 129. A screen on the outside of the casting, not shown in FIG. 28a, filters the air. Four studs 173, nuts 1'74 and lockplate 175 fasten the unit to the pump side of the spindle. A gasket 176 between them seals all passages in the spindle on the pump side, except the air inlet, water inlet and stud holes.

The machine will not start until the liquid ring has been established. Assuming that it contains no water at all, it is therefore essential that water enters as soon as possible. This suggests using water itelf for the purpose of starting by injecting it at high speed through one or more nozzles 177, shown in FIG. 23, While an inlet 178 is provided for such a nozzle in FIG. 24. The water jet will follow the contour of the oval, spread out and impact on the rotor vanes. Since the rotor is supported on ball and roller bearings, it will spin easy until the liquid ring is partially established. The water impact can be supplemented by supplying compressed air to the air motors or even to the product gas motor. Air and even water under pressure can be accumulated in one common or two separate tanks or be drawn from utility lines. Within two or three seconds the machine will start pumping, after which it will rapidly come to rated power and speed.

When the machine is stopped, the water will gather in the lower half, which will make it d-iificult to start the next time. Therefore, a water drain system has been provided, consisting of a header 179, fed by the branches 180, 181, 182 and 183. These branches are drilled from the outside of the header and sealed by the plug 184.

To prevent overfilling the machine with water, Water level controls are provided on the inside of each end cover 52. They both consist of a ring 185 clamped between the cover and the spacer ring 163. This ring 185 is shown in cross section in FIG. 6 and in a plane perpendicular thereto in FIG. 29a. On the bottom it carries a skimmer 186 which passes any surplus water up into a hole 187 that communicates with the outlet opening 188 in the cover.

Ring 1255 is also provided with a hole 189 at the top, which toward the outside connects with the lubricant supply opening 190 in the end cover 52. Any oil introduced in this opening flows through the hole 191 into a groove on the inside of the spacer ring 163 toward the ball bearing 67 or the roller bearing 68.

FIG. 32 diagrammatically shows a piping diagram for the refrigerator system in which:

V1 is the valve for control of the starting water.

V2 is the valve for control of draining the machine.

V3 is the valve for control of natural gas supply.

V4 is the valve for control of make-up water.

V is the valve for control of the cooling water jet pump.

V1, V2 and V5 are solenoid valves, that are either wide open or closed, V3 may be controllable within the 10 limits of inflammability, a range of about 3 to 1, the air intake in the gas-air mixer being constant. V4 must be controllable over a wide range, so that it may be ad justed until only a slight drip continually comes from the skimmers 186.

In operation V1 and V2 are closed, while V3 and V5 are open. To shunt down, V3, V4 and V5 are closed and V2 is opened. Since at least the end sections are vented through the skirnmers, these will drain rapidly and the pump and motor section will follow more slowly.

For starting V2 is closed, V1 and V5 are opened wide and V3 partially, while the glowplug is energized. At the first sign of temperature rise in the combustor V1 is closed, V3 and V4 are opened wide. When the maximum gas pressure is reached, the current to the glowplug is cut off, while V4 is adjusted for the minimum skimmer flow.

The compressed gas and air issuing from the pumps are delivered to two separators, where the water is collected and made to join the stream of cooling water coming from the jet pump. The gases reach the combustor separately, to be mixed after ignition. The cooling water, mixed with the sealing water from the pumps, goes through the radiator part of the condenser.

The Freon-water mixture goes straight to the condenser, whereupon the liquids are separated by gravity as shown, the Freon being about 50% heavier than water. From here the water is mixed with the stream coming from the radiator to be returned to the motor as cooling water. The liquified Freon goes via the capillary tubes to the evaporator, where it abstracts heat from the air stream pumped over the coils by the circulating fan. After vaporization it returns to the Freon pump.

FIG. 33 shows a liquid piston engine with an output shaft for multiple V-belt drive. The motor side of the housing 192 and rotor differ from those of the machine shown in FIG. 6 only, in that the roller bearing 68 and the oil seals 71 and 73 have been replaced by a ball bearing 193 and the oil seals 194 and 195. This means that a modified bearing retainer 196 and bearing housing 197 are needed, but the motor wheels 74 and 75 remain unchanged. Also the cover 52, the ring and the spacer ring 163 are the same as before and so are the gas, air and exhaust collector rings, the gas distributing ring, the nut 58 and spacer 161, but the product gas distributor inlet 198 was modified for clearance. However, except for the air entrance 199, all gas inand outlets were moved to the motor side.

The pump side now contains only the impeller for the gas pump 200 and for the air pump 201. Also the bearing housing was changed to a housing 202, which contains only the oil seal 203 and has been adapted for attachment of the flange 204 of the output shaft 205. This shaft is supported by two ball bearings 206 and 207, mounted in the housing 208, which also serves as end cover for the stator housing 192 and supports a skimmer 209 for draining excess water via the hole 210 and the outlet 211. Bearing 207 carries a snapring 212, which 10- cates it axially between the housing 208 and its cover 213. The shaft 205 carries the sheave 214 having a hub 215. The nut 216 clamps this hub, the inner race 217, the spacer 218 and the inner race 219 against the shoulder 220 on the flange 204.

The shaft further has an extension 221, provided with a groove for the snapring 222 to retain the pilot bearing 223, which fits in the counterbore 224 in the spindle 225. Thus on the pump side the spindle is indirectly supported by the end cover 208.

The water and gas passages in the spindle have been altered to fit the new organization of parts. FIGS. 35 through 43 show the new arrangement and it will be seen that FIGS. 37, 38, 40 and 43 correspond respectively with FIGS. 10, 11, 15 and 12. Further FIGS. 36, 39 and 41 show two diiferent ways of furnishing water under pressure to the critical areas. The last two duplicate the method of FIG. 2%, but in FIG. 36 only the hole 226 1 1 has been drilled, while the slot 227 substitutes or the holes 228 or 229. It will also be noticed that three pairs of holes 230, 231 and 232 have been drilled in an axial direction from the end face 233 of the spindle in the metal outside of the pilot bearing 223. All six of these have been plugged at the end face. Of these 230 and 231 run until they meet 229 and 226 at station 41. Both pairs pass small cross drills at the end partition of the housing 202 and serve for the purpose of sealing the crititical areas in this partition. The sealing Water comes from the supply at station 41.

The holes 232 break into the air intake ports 234 of the air pump. They pass cross drills between the two contact lips of the oil seal 203, thus reducing the pressure in the space between these lips to atmospheric, with the result that any air or water entering this space is eliminated. The hole 235 in FIG. 35 performs the same function for oil seal 195 by venting it into the gas intake, so that any Water bleeding through with the air may be recovered. Holes 9 and 17 in FIGS. 6, 9 and 17 are there for the same reason. 7

The Water circulation castings 236 and 237 also differ from those used before. Cooling water enters at 238, flows into the cavity 239, from where it enters the pipe 240. It returns via the holes 241 and the annulus 242 and leaves the unit 236 at 243. Make-up water enters at 244, passes through the hole 245, from where it enters the tube 246, which at the end is closed off by the plug 247 with the orifices 248, from which it squirts in the direction of the air intake ports 234.

The water ciculation castings are separated from each other by the gasket 249 and from the spindle by a gasket 250 that seals all openings for the gas passages, except water and stud holes.

The water drain system of the machine of FIG. 33 is the same as that of FIG. 6.

The method of starting may be the same as described for the motor-refrigerant pump, or it is possible to utilize a conventional automotive electric starting system together with low pressure water injection.

While two embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise, without departing from such principles.

It must be pointed out that the very low pressure used for the refrigeration condenser is a function of the refrigerant chosen and by no means the limit of the liquid piston machine. Liquid piston pumps have been used to compress air to 100 p.s.i.a. using water as the liquid. Much higher pressures can be obtained by double staging or using heavy liquids, such as acetylene tetrabromide, mercury and others.

In the appended claims the following definitions apply: An IMPELLER is a disc associated with a pump carrying equally spaced, axially protruding vanes.

A WHEEL is a disc associated with a motor carrying equally spaced, axially protruding vanes.

A ROTOR is the assembly of all impellers, wheels and other rotating parts supported by two or more bearings. Outside and inside surfaces of the rotor are concentric with its centerline of rotation.

A STATOR SPINDL'E is a stationary cylindrical shaft having an outside diameter sized to slide inside the rotor. At the location of each impeller or wheel the outside surface is provided with intake and exhaust ports, which are depressions each communicating with one of several longitudinal passages inside the spindle. The spindle is further provided with hearings to support the rotor.

ECCENTRICITY is the distance between the centerline of the rotor andthe centerline of a cylindrical segment on the housing. The eccentricity is positive or negative, dependent on whether the centerline and the segment 12 are on the same or on opposite sides of the centerline of the rotor. ,A LOBE is a cylindrical segment having a centerline with positive eccentricity.

A FLANK is a cylindrical segment having a centerline with zero or negative eccentricity. The rotor always approaches the midpoint of a flank within running clearance.

A STATOR HOUSING is a stationary housing surrounding the rotor. The centerline of housing and rotor coincide. Wherever there are wheels or impellers on the rotor, the cross section of the housing is composed of equally spaced identical lobes, halfway between which there are identical flanks. The end sections of 15 the housing may have round cross sections concentric with the rotor. At the transitions between end, wheel and impeller sections, the housing has radial partitions bored out to permit rotation of the rotor. A LIQUID RING is a layer of liquid on the inner surfaces of the stator housing accumulated under the influence of a centrifugal force field caused by the rotation of wheels, impellers or other parts carrying vanes when the stator housing is filled with sufiicient liquid to keep the vane tips submerged. A MIXTURE is an inflammable mixture of fuel and air. A PRODUCT GAS is a gas composed of the products of combustion of a mixture with or without air dilution. A COMBUSTOR is a device for igniting compressed mixture with a glowplug or flame holder, combusting it at constant pressure and mixing the products with air.

I claim:

1. In a liquid piston machine a com bustor and a unitary structure comprising a plurality of pumps and motors including an air pump, a mixture pump and a product gas motor interposed between two air motors, said pumps and motors having individual rotors coaxially connected to each other and adapted for rotation about a stationary member, means for taking the influx to the air pump out of the atmosphere and for feeding a mixture of fuel and air to the mixture pump, means for delivering the compressed efflux of said mixture pump and part of the compressed air issuing from said air pump to said combustor, means for supplying the outflow of the combustor to the product gas motor and part of the compressed air to the air motor and means for discharging the exhaust gas of said motors into the atmosphere.

2. The device of claim 1, including a stator housing divided in sections by partition walls, a stator spindle, end covers to close said housing and support said spindle, a rotor on said spindle, said sections having a cross section in the form of one or more equally spaced lobes extending radially outward from the rotor starting at a point of near contact with said rotor, the pump section being angularly displaced with respect to the motor section through an angle of approximately 60 in the direction of rotation about the centerline of said rotor, means for forming a liquid ring in said stator housing and means for rapidly draining the content of the liquid ring simultaneously from all sections of the stator 60 housing.

'3. The device of claim 2, means for delivering the remaining outflow of the air pump for external use.

4. The device of claim 3, rings around an extension of the stator spindle external to an end cover, each of said 60 rings having an internal groove communicating with an opening on the outside of the ring, holes in the spindle extension at the location of each ring groove, said holes terminating in the longitudinal passages inside the spindle, said passages leading to the ports of the various motors and pumps.

5. The device of claim 3, means for separating the liquid from the outflow of the pumps, means for cooling said liquid and for introducing it into a passage inside the stator spindle for the purpose of cooling the spindle said passage running parallel to the passages 13 leading to the intake and exhaust ports of the product gas motor, means for bleeding some of the liquid into the motors and for returning the remainder to the liquid separated from the outflow of the pump.

6. The device of claim 3, means for injecting one or more high velocity liquid jets in the direction of rotation into one or more of the lobes of the stator housing for the purpose of accelerating the rotor and reestablishing a liquid ring in the machine, when it is empty and at rest.

7. The device of claim 2, including two air pumps, a mixture pump and a gas compressor, said compressor being interposed between the two air pumps, said air pumps starting compression sufliciently later than the gas pump, so as to accomplish the maximum desired pressure in the gas and air pumps simultaneously, means for joining the intake and exhaust ports of the two air pumps and means for feeding gas to the intake ports of the gas compressor and delivering the outflow for external use.

8. The device of claim 7, rings around an extension of the stator spindle external to an end cover, each of said rings having an internal groove communicating with an opening on the outside of the ring, holes in the spindle extension at the location of each ring groove, said holes terminating in the longitudinal passages inside the spindle, said passages leading to the ports of the various motors and pumps.

9. The device of claim 7, means for separating the liquid from the outflow of the pumps, means for cooling said liquid and for introducing it into a passage inside the stator spindle for the purpose of cooling the spindle, said passage running parallel to the passages leading to the intake and exhaust ports of the product gas motor, means for bleeding some of the liquid into the motors and for returning the remainder to the liquid separated from the outflow of the pumps.

10. The device of claim 7, means for injecting one or more high velocity liquid jets in the direction of rotation into one or more of the lobes of the stator housing for the purpose of accelerating the rotor and reestablishing a liquid ring in the machine, when it is empty and at rest.

11. The device of claim 2, including a power output shaft attached to the rotor, having provision for supporting one side of the spindle, and bearings in one end cover to support said power output shaft.

12. The device of claim 11, rings around an extension of the stator spindle external to an end cover, each of said rings having an internal groove communicating with an opening on the outside of the ring, holes in the spindle extension at the location of each ring groove, said holes terminating in the longitudinal passages inside the spindle, said passages leading ,to the ports of the various motors and pumps.

13. The device of claim 11, means for separating the liquid from the outflow of the pumps, means for cool ing said liquid and for introducing it into a passage inside the stator spindle for the purpose of cooling the spindle, said passage running parallel to the passages leading to the intake and exhaust ports of the product gas motor, means for bleeding some of the liquid into the motors and for returning the remainder to the liquid separated from the outflow 'of the pumps.

14. The device of claim 11, means for injecting one or more high velocity liquid jets in the direction of rotation into one or more of the lobes of the stator housing for the purpose of accelerating the rotor and reestablishing a liquid ring in the machine, when it is empty and at rest.

15. The device of claim 11, including starting means driving the output shaft, while admitting liquid to the stator housing to reestablish the liquid ring in the machine, When it is empty and at rest.

References Cited by the Examiner UNITED STATES PATENTS 1,014,330 1/1912 Reeve 39.18 2,136,527 11/1938 Stelzer 230-79 X 2,618,431 11/1952 Walker 230116 X ROBERT M. WALKER, Primary Examiner. 

1. IN A LIQUID PISTON MACHINE A COMBUSTOR AND A UNITARY STRUCTURE COMPRISING A PLURALITY OF PUMPS AND MOTORS INCLUDING AN AIR PUMP, A MIXTURE PUMP AND A PRODUCT GAS MOTOR INTERPOSED BETWEEN TWO AIR MOTORS, SAID PUMPS AND MOTORS HAVING INDIVIDUAL ROTORS COAXIALLY CONNECTED TO EACH OTHER AND ADAPTED TO ROTATION ABOUT A STATIONARY MEMBER, MEANS FOR TAKING THE INFLUX TO THE AIR PUMP OUT OF THE ATMOSPHERE AND FOR FEEDING A MIXTURE OF FUEL AND AIR TO THE MIXTURE PUMP, MEANS FOR DELIVERING THE COMPRESSED EFFLUX OF SAID MIXTURE PUMP AND PART OF THE COMPRESSED AIR ISSUING FROM SAID AIR PUMP TO SAID COMBUSTOR, MEANS FOR SUPPLYING THE OUTFLOW OF THE COMBUSTOR TO THE PRODUCT GAS MOTOR AND PART OF THE COMPRESSED AIR TO THE AIR MOTOR AND MEANS FOR DISCHARGING THE EXHAUST GAS OF SAID MOTORS INTO THE ATMOSPHERE. 